PPRuNe Forums - View Single Post - Air Asia Indonesia Lost Contact from Surabaya to Singapore
Old 1st Jan 2015, 09:49
  #832 (permalink)  
NigelOnDraft
 
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If the CAS measurements for the three ADR are lower than 60 kt, the angle of attack values of the three ADR are invalid and the stall warning is then inoperative.
Roseland, spot on!!
....
Someone is culpably negligent in such a design flaw.
At what speed, and how derived, do you suggest the STALL warning is enabled/disabled? At low speed, "how" do you proipose to measure AoA in order to drive the "STALL" warning?

I note Roseland omits the explanation for the 60K cutoff:
This results from a logic stating that the airflow must be sufficient to ensure a valid measurement by the angle of attack sensors, especially to prevent spurious warnings on the ground.
Do we really want the STALL warning shouting at us until mid takeoff run??

Airbus' and other modern aircraft are clever, but they cannot rewrite the laws of physics. Even my little homebuilt aeroplane has a speed based "cutoff" for AoA (Stall) warnings.


PS I do not see WoW as a "better" solution, since the LGCIUs sense that, and fail relatively frequently, and MEL permits dispatch with 1 U/S. Do we really want to disable STALL watning for simple LGCIU problems?
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